Ireland: where to swim in October?
Ireland, in October: the sea is at 13.7 °C on average along the coast, from 12.9 °C to 14.3 °C depending on the spot. Where the water is warmest (14.3 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.
Sea temperature, month by month
| Month | Average temperature | Depending on the spot | Where it is warmest |
|---|---|---|---|
| January | 9.9 °C | 9.2 °C – 10.4 °C | cold |
| February | 9.4 °C | 8.5 °C – 10.2 °C | cold |
| March | 9.4 °C | 8.5 °C – 10.2 °C | cold |
| April | 10.0 °C | 9.2 °C – 10.6 °C | cold |
| May | 11.5 °C | 10.8 °C – 12.1 °C | cold |
| June | 13.6 °C | 12.9 °C – 14.5 °C | cold |
| July | 15.2 °C | 14.2 °C – 16.4 °C | cool |
| August | 15.8 °C | 14.9 °C – 16.5 °C | cool |
| September | 15.0 °C | 14.2 °C – 15.7 °C | cool |
| October | 13.7 °C | 12.9 °C – 14.3 °C | cold |
| November | 12.2 °C | 11.6 °C – 12.8 °C | cold |
| December | 10.8 °C | 10.4 °C – 11.2 °C | cold |
Compared with September, the water cools down by 1.3 °C in October. The warmest month: August (15.8 °C). The coldest: February (9.4 °C).
Nearby, in October
- United Kingdom 12.9 °C · cool
- Netherlands 15.2 °C · cool
- France 18.0 °C · pleasant
- Denmark 13.0 °C · cold
- Germany 13.7 °C · cold
- Portugal 19.6 °C · pleasant
And right now?
At sea, 13.5 °C on average across 8 stations, from 11.0 °C (Bouée de Lehanagh Pool (Connemara)) to 15.3 °C (K1 Buoy). Ireland: water temperature
Frequently asked questions
What is the sea temperature in October?
Ireland, in October: 13.7 °C on average along the coast, from 12.9 °C in the coolest waters to 14.3 °C in the warmest (average of the years 2011 to 2025).
Can you swim in October?
Where the water is warmest (14.3 °C), it is cold. You can swim, but the cold bites quickly: plan a short swim, or wear a wetsuit.
What is the best month for swimming?
The water is warmest in August (15.8 °C on average) and coldest in February (9.4 °C). Even where it is warmest, the water never reaches 20 °C in any month; the three warmest months are: August, July, September.
Where is the water warmest in October?
The warmest in October: United Kingdom (12.9 °C), Netherlands (15.2 °C), France (18.0 °C). The coolest: Portugal (19.6 °C).
Where do these temperatures come from?
These are averages of the sea surface temperature from 2011 to 2025, computed from NOAA satellite images (OISST, one value about every 50 km), in a 100 km strip along the coasts of the main country: distant territories (overseas, remote islands) are not counted. It is an estimate, not a measurement taken at the beach: lakes and rivers are not included.